From the tweet:

EXCLUSIVE: Katherine Maher says that she abandoned a "free and open" internet as the mission of Wikipedia, because those principles recapitulated a "white male Westernized construct" and "did not end up living into the intentionality of what openness can be."

There is a video of her speaking, which I find hard to translate.

Most recent are a reasonably mundane culture wars stuff but (more interesting to HN) it seems earlier Signal related ones appear to suggesting a degree of alignment with the USA government. The words "spook" and "compromised" are used in different comments.

Edits. From the Signal page:

"She is an appointed member of the U.S. Department of State's Foreign Affairs Policy Board, where she advises the Secretary of State on technology policy"

which may explain some of it. It reminds me of an odd experience I had with Wikipedia around covid time - I edit a bit and thought you could say covid may have arisen zoonotically like all previous such pandemics or may have come from the nearby lab which was running job ads for bat coronavirus researchers at the time of the outbreak and as an open wiki you could consider both but no - the lab stuff was largely verboten and unmentionable. I guess the above article explains a bit how that happened maybe?